"To all modern Sons of Liberty: THIS is your time. Break their windows. Break them NOW."

These were the words of Mike Vanderboegh, a 57-year-old former militiaman from Alabama, who took to his blog urging people who opposed the historic health-care reform legislation -- he calls it "Nancy Pelosi's Intolerable Act" -- to throw bricks through the windows of Democratic offices nationwide.

"So, if you wish to send a message that Pelosi and her party [that they] cannot fail to hear, break their windows," Vanderboegh wrote on the blog, Sipsey Street Irregulars. "Break them NOW. Break them and run to break again. Break them under cover of night. Break them in broad daylight. Break them and await arrest in willful, principled civil disobedience. Break them with rocks. Break them with slingshots. Break them with baseball bats. But BREAK THEM."

In the days that followed, glass windows and doors were shattered at local Democratic Party offices and the district offices of House Democrats from Arizona to Kansas to New York. At least 10 Democratic lawmakers reported death threats, incidents of harassment or vandalism at their offices over the past week, and the FBI and Capitol Police are offering lawmakers increased protection.

Local Democratic Party officials in New York have called for Vanderboegh's arrest, believing he is implicated in the vandalism in Rochester, but Vanderboegh said he has not yet been questioned by any law enforcement authorities.

Vanderboegh was unapologetic in a 45-minute telephone interview with The Washington Post early Thursday. He said he believes throwing bricks through windows sends a warning to Democratic lawmakers that the health-care reform legislation they passed Sunday has caused so much unrest that it could result in a civil war.

"The federal government should not have the ability to command us to buy something that it decides we should buy," Vanderboegh said. The government, he added, has "absolutely no idea the number of alienated who feel that their backs are to the wall are out here . . . who are not only willing to resist this law to the very end of their lives, but are armed and are capable of making such resistance possible and perhaps even initiating a civil war."

The law will set in motion over the next 10 years a complex series of changes to the nation's health insurance market. An estimated 24 million people who lack access to affordable coverage through their workplace will be eligible for tax credits to buy insurance on new state-based exchanges. Nearly everyone who earns less than 133 percent of the federal poverty level will become eligible for the government-run Medicaid. And for the first time, individuals will face fines of as much as $695 a year for refusing to buy insurance, and employers with more than 50 workers that do not provide coverage could also face significant fines.

Vanderboegh said House Speaker Nancy Pelosi (D-Calif.) and House Democrats should beware "unintended consequences of their actions." Vanderboegh outlined a complicated theory that IRS agents will go after people who refuse to buy insurance or pay the fines, ultimately resulting in "civil war."

"The central fact of the health-care bill is this, and we find it tyrannical and unconstitutional on its face," Vanderboegh said. "The federal government now demands all Americans to pay and play in this system, and if we refuse, we will be fined, and if we refuse to pay the fine, they will come to arrest us, and if we resist arrest . . . then we will be killed. The bill certainly doesn't say that, but that's exactly and precisely what is behind every bill like this."

He said his call for people to throw bricks is "both good manners and it's also a moral duty to try to warn people."

Vanderboegh, who lives in the Birmingham suburb of Pinson, described himself as a "Christian libertarian" and said he has long been a gun rights advocate. He said he joined a clandestine militia group called the "Sons of Liberty" and later became a public leader of the First Alabama Cavalry, Constitutional Militia.

In 2006, Vanderboegh advocated hurling bricks through the windows of members of Congress who supported giving illegal immigrants the same rights as U.S. citizens, according to news reports at the time. He said those bricks should be used to build a wall sealing off the United States from Mexico.

Vanderboegh has no criminal record in Jefferson County, Ala., according to a court clerk there.

The Southern Poverty Law Center, which tracks extremist and hate groups, has been following Vanderboegh since the mid-1990s, when he first surfaced in Alabama militia groups, said Heidi Beirich, the center's research director.

"He has been on our radar forever," she said. "He hasn't been involved in any kind of violence that we know of ourselves, but these causes that he's involved in led to a lot of violence. The ideas that Vanderboegh's militia groups were pushing were the same extreme anti-government ideas that inspired [Timothy] McVeigh in the Oklahoma City bombing."

Vanderboegh said he once worked as a warehouse manager but now lives on government disability checks. He said he receives $1,300 a month because of his congestive heart failure, diabetes and hypertension. He has private health insurance through his wife, who works for a company that sells forklift products.

Born in Michigan and raised in Ohio, Vanderboegh said he was not always a libertarian. He once was active in the Young Socialist Alliance and the Progressive Labor Party. "In my youth, I was a communist," he said. But in the mid-1970s, Vanderboegh read Friedrich von Hayek's "The Road to Serfdom," among other books, and had an epiphany.

"From that point on, I could never take Marxism-Leninism seriously again," Vanderboegh said.

He said he long opposed President Obama because he believed the president has "collectivism" tendencies. But he became especially energized during the health-care debate.

Vanderboegh said he advocates breaking windows only of Democratic Party offices, not congressional offices, and that he does not condone the death threats and other incidents of harassment that some Democratic lawmakers have faced.

"Obviously I not only deplore or decry that, but I denounce that vigorously because it has nothing to do with what I was advocating," he said.

Still, Vanderboegh's public cry for vandalism has made him vulnerable to the same threats.

"Frankly," he said, "my phone's been ringing off the hook with death threats the last few days."